1. Technical Field
The present disclosure relates to a process for the alkylation, and particularly to a process for the alkylation of paraffins with olefins to produce gasoline products.
2. Background of the Art
Alkylation processes for the manufacture of high octane gasoline products are known. Typically, such processes are directed to the alkylation of paraffins with olefins to produced branched hydrocarbon molecules for gasoline components such as isomers of trimethylpentane (TMP), which have high octane numbers. High octane number, i.e., research octane number (“RON”), is important for gasoline, especially gasolines for use in high performance automobile engines to prevent engine knock.
Liquid alkylation using acid catalysts is a commonly used method for olefin-paraffin alkylation. Two commonly used processes employ sulfuric acid or hydrofluoric acid. However, both of these methods suffer from severe environmental hazards. Both acids are highly corrosive and dangerous if released.
Solid olefin-paraffin alkylation processes are also known. Such processes typically employ a solid catalyst such as transition metals or metals of Group VIII of the Periodic Table of the Elements (particularly noble metals) in combination with a zeolite, silica, alumina, silica-alumina, oxides of transition metals such as zirconium, molybdenum, tungsten, titanium or tin, for example.
Suitable zeolites for use as solid olefin-paraffin alkylation include zeolite Y, HY, USY, zeolite beta, MCM-22 and MCM-36, for example.
U.S. Pat. No. 5,986,158, which is herein incorporated by reference, discloses a process for alkylating hydrocarbons in which an alkylatable organic compound is reacted with an alkylating agent to form an alkylate in the presence of a catalyst providing a hydrogenating function and a solid acid constituent, with the catalyst being subjected intermittently to a regeneration step by being contacted with a feed containing a saturated hydrocarbon and hydrogen.
A problem remains with solid catalyst alkylation processes in that the catalyst has a relatively short on-stream life and needs to be repeatedly regenerated. Clearly, it would be desirable to have a catalyst with a longer on-stream life, thereby requiring less frequent regeneration cycles.